J. Koch, M.D. of Brookline Women's Healthcare Associates has submitted a proposal to develop an improved cervical cap for barrier contraception. He states that currently available prefabricated cervical caps are ill fitting, are easily dislodged and provide an unacceptably high pregnancy rate. Experience, to date, suggests that a custom fitted cap might provide a means of long-term wear without dislodgement. The applicant proposes to 1) explore and improve methods of taking cervical impressions in an effort to develop a custom fitted cap, 2) develop caps of various materials and design, and 3) test various cap models in vivo.